نتایج جستجو برای: weightlessness

تعداد نتایج: 445  

2017
Mu Zhu Zhongyang Liu Mingze Gao Yan Zhang Yuheng Li Shukuan Ling Pengfei Zhang Chenyang Zhao Lijun Jiang Yu Liu Qi Li Dong Li Sumin Hu Yingxian Li

Microgravity has been previously demonstrated to induce skeletal muscle atrophy, loss of muscle force and disorders in myogenesis and metabolism. Current pharmacological strategies exhibit poor efficacy. Bu Zhong Yi Qi decoction (BZ) is a well‑known traditional Chinese medicine decoction used for myasthenia gravis. In the present study, its effect on unloading induced muscle atrophy was investi...

Journal: :Sheng li xue bao : [Acta physiologica Sinica] 2011
Jun-chan Ren Xiao-li Fan Xin-ai Song Lei Shi

The present study aimed to study the changes of neurotrophin-3 (NT-3) expression of intrafusal muscle fibers in rat soleus muscles under simulated weightlessness. The tail-suspension (SUS) rat model was used to simulate weightlessness. Forty mature female Sprague-Dawley rats were randomly assigned to ambulatory control (CON), 3-day SUS, 7-day SUS, 14-day SUS and 21-day SUS groups. Immunohistoch...

Journal: :Aviation, space, and environmental medicine 1988
C A Blamick D J Goldwater V A Convertino

Ten men (35-49 years old) underwent lower body negative pressure (LBNP) exposures before and after 10 d of continuous 6 degrees head-down bedrest in order to predict the effect of weightlessness on the responsiveness of leg vasculature to an orthostatic stress. Heart rate (HR), mean arterial blood pressure (MAP), and impedance rheographic indices of arterial pulse volume (APV) of the legs were ...

Journal: :The Journal of aviation medicine 1951
H HABER S J GERATHEWOHL

T H E D E V E L O P M E N T of aviation is directed toward ever increasing velocities and altitudes. Already, today, aircraft fly at altitudes at which the density of the atmosphere is extremely low. According to the principles of mechanics, reduction or entire lack of weight will ensue during coasting maneuvers at high altitudes because mechanical support by the atmosphere is lacking/ Conseque...

Journal: :Journal of applied physiology 2008
Wen Yin Jin-Cheng Liu Rong Fan Xi-Qing Sun Jin Ma Na Feng Quan Yu Zhang Zhao Yin Shu-Miao Zhang Hai-Tao Guo Hui Bi Yue-Min Wang Xin Sun Liang Cheng Qin Cui Shi-Qiang Yu Ding-Hua Yi Jian-Ming Pei

The modulation of beta-adrenoceptor signaling in the hearts of hindlimb unweighting (HU) simulated weightlessness rats has not been reported. In the present study, we adopted the rat tail suspension for 4 wk to simulate weightlessness; then the effects of simulated microgravity on beta-adrenoceptor signaling were studied. Mean arterial blood pressure (ABP), left ventricular pressure (LVP), syst...

2017
Nara Yoon Kiyong Na Hyun-Soo Kim

Spaceflight induces pathophysiological alterations in various organs. To study pathophysiological adaptations to weightlessness on the ground, the tail suspension (TS) rat model has been used to simulate the effects of weightlessness. There is currently little information on the effect of TS on the expression and activity of nitric oxide synthase (NOS) in the brain. In this study, we examined t...

Journal: :Journal of applied physiology 1999
B Pump R Videbaek A Gabrielsen P Norsk

Results from our laboratory have indicated that, compared with those of the 1-G supine (Sup) position, left atrial diameter (LAD) and transmural central venous pressure increase in humans during weightlessness (0 G) induced by parabolic flights (R. Videbaek and P. Norsk. J. Appl. Physiol. 83: 1862-1866, 1997). Therefore, because cardiopulmonary low-pressure receptors are stimulated during 0 G, ...

Journal: :Acta veterinaria 2003
P Skrobanek M Hrancova

The objective of this study was to evaluate the adaptability of young Japanese quail chicks to the simulated weightlessness, represented by hypodynamy. Unsexed hatchlings were subjected to hypodynamy on either the first, second or third day of age and reared under these conditions to 21 days of age. During this period, the control quail chicks were housed in a floor box. The effect of hypodynam...

2003
Ian P. Howard Theodore Smith Andrew C. Beall Alan Natapoff James E. Zacher

In weightlessness, astronauts must rely on vision to remain spatially oriented. Although gravitational "down" cues are missing. most astronauts maintain a "subjective vestical"-a subjective sensc of which way is up. This is evidenced by anecdotal reports of crewmembers feeling upside down (inversion illusions) or feeling that a floor has become a ceiling and vice versa (visual reorientation ill...

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